Tornadoes

A tornado is a violently rotating column of air that extends from a thunderstorm and comes into contact with the ground, according to the National Oceanic and Atmospheric Administration (NOAA). In an average year about 1,000 tornadoes are reported nationwide, according to NOAA. Tornado intensity is measured by the enhanced Fujita (EF) scale. The scale rates tornadoes on a scale of 0 through 5, based on the amount and type of wind damage. It incorporates 28 different damage indicators, based on damage to a wide variety of structures ranging from trees to shopping malls.

The U.S. experiences more tornadoes than any other country in the world, according to a 2013 report by Lloyd’s of London. (See Executive Summary, page 4 of Tornadoes a Rising Risk? for additional findings and statistics.)

Source: U.S. Department of Commerce, National Oceanic and Atmospheric Administration.

2020 Tornadoes: In 2020 through May there were 602 tornadoes compared with 932 in 2019, according to the National Oceanic and Atmospheric Administration (NOAA). In 2020 through May, 73 people perished in tornadoes compared with 38 in 2019. March 3, 2020 was a particularly deadly day as 24 people perished in tornadoes in central Tennessee, including the city of Nashville.

2019 Tornadoes: Preliminary NOAA reports show there were 1,520 tornadoes in 2019 compared to 1,126 in 2018. Tornadoes killed 41 people in 2019, compared with 10 people in 2018.

On March 3, 2019 a tornado struck southeast Alabama as part of a severe storm system that resulted in catastrophic damage in Alabama, Georgia, South Carolina and Florida. Twenty-three people were killed in the March 3 tornado in Lee County, Alabama. In Beauregard, Alabama, the tornado left a half-mile wide path of destruction. The National Weather Service said that the tornado was F4 strength with top winds of 170 miles per hour. The tornado storm system of March 3 was the deadliest outbreak in the United States since a system in Arkansas and Mississippi in April 2014 killed 35 people.

There were 272 tornadoes in April which caused seven deaths: two each in Texas, Louisiana and Oklahoma and one in Mississippi. There were 506 tornadoes recorded in May, the worst month for tornadoes in 2019. These tornadoes claimed another seven lives, including three in Missouri, two in Oklahoma and one each in Iowa and Ohio. Tornadoes from May 26 to May 29 in 13 states caused $3.4 billion in losses, according to the Property Claim Services unit of ISO. On October 20 and 21, a severe thunderstorm outbreak ripped through Texas, Oklahoma, Missouri, Arkansas, Tennessee and Louisiana, and produced several tornadoes including an EF-3 affecting the Dallas, Texas area. Aon said insured losses may reach the hundreds of million dollars. In December 72 tornadoes formed, causing two deaths in Alabama and one in Louisiana.

Insured Losses

The United States experiences more tornadoes than any other country. Tornadoes accounted for 39.9 percent of insured catastrophe losses from 1997 to 2016, according to Verisk’s Property Claim Services (PCS). A March 2017 report by Willis Re found that the average annual loss from severe convective storms is $11.23 billion (in 2016 dollars) compared to $11.28 billion from hurricanes, based on PCS data. In 2018, insured losses from U.S. tornadoes/thunderstorms totaled $14.1 billion, up from $18.2 billion in 2017, according to Munich RE. The National Oceanic and Atmospheric Administration notes that tornadoes can happen any time of year. The costliest U.S. catastrophe involving tornadoes, based on insured losses, occurred in April 2011. It hit Tuscaloosa, Alabama, and other areas, and cost $8.2 billion in insured damages (in 2018 dollars). The second costliest catastrophe involving tornadoes, based on insured losses, struck Joplin, Missouri, and other locations in May 2011. The catastrophe cost $7.8 billion in insured losses in 2018 dollars. (See chart below.) The National Weather Service posts updated information on tornadoes.

(1) Based on data through April 17, 2020.
(2) Property coverage only. In addition to losses due to tornadoes themselves, amounts may include losses due to hail, wind and flooding during the same event.
(3) Adjusted for inflation through 2019 by the Insurance Information Institute using the GDP implicit price deflator.

(1) Ranked by total number of tornadoes.
(2) States with the same number of tornadoes receive the same ranking.
(3) State had no tornadoes in 2019.
(4) The U.S. total will not match data used in other charts because it counts tornadoes that cross state lines.